| 1 | // -*- mode: cpp; mode: fold -*- |
| 2 | // Description /*{{{*/ |
| 3 | // $Id: cdromutl.cc,v 1.12 2001/02/20 07:03:17 jgg Exp $ |
| 4 | /* ###################################################################### |
| 5 | |
| 6 | CDROM Utilities - Some functions to manipulate CDROM mounts. |
| 7 | |
| 8 | These are here for the cdrom method and apt-cdrom. |
| 9 | |
| 10 | ##################################################################### */ |
| 11 | /*}}}*/ |
| 12 | // Include Files /*{{{*/ |
| 13 | #include<config.h> |
| 14 | |
| 15 | #include <apt-pkg/cdromutl.h> |
| 16 | #include <apt-pkg/error.h> |
| 17 | #include <apt-pkg/md5.h> |
| 18 | #include <apt-pkg/fileutl.h> |
| 19 | #include <apt-pkg/configuration.h> |
| 20 | #include <apt-pkg/strutl.h> |
| 21 | |
| 22 | #include <sys/wait.h> |
| 23 | #include <sys/statvfs.h> |
| 24 | #include <dirent.h> |
| 25 | #include <fcntl.h> |
| 26 | #include <sys/stat.h> |
| 27 | #include <unistd.h> |
| 28 | #include <stdio.h> |
| 29 | |
| 30 | #include <apti18n.h> |
| 31 | /*}}}*/ |
| 32 | |
| 33 | using std::string; |
| 34 | |
| 35 | // IsMounted - Returns true if the mount point is mounted /*{{{*/ |
| 36 | // --------------------------------------------------------------------- |
| 37 | /* This is a simple algorithm that should always work, we stat the mount point |
| 38 | and the '..' file in the mount point and see if they are on the same device. |
| 39 | By definition if they are the same then it is not mounted. This should |
| 40 | account for symlinked mount points as well. */ |
| 41 | bool IsMounted(string &Path) |
| 42 | { |
| 43 | if (Path.empty() == true) |
| 44 | return false; |
| 45 | |
| 46 | // Need that trailing slash for directories |
| 47 | if (Path[Path.length() - 1] != '/') |
| 48 | Path += '/'; |
| 49 | |
| 50 | /* First we check if the path is actualy mounted, we do this by |
| 51 | stating the path and the previous directory (carefull of links!) |
| 52 | and comparing their device fields. */ |
| 53 | struct stat Buf,Buf2; |
| 54 | if (stat(Path.c_str(),&Buf) != 0 || |
| 55 | stat((Path + "../").c_str(),&Buf2) != 0) |
| 56 | return _error->Errno("stat",_("Unable to stat the mount point %s"),Path.c_str()); |
| 57 | |
| 58 | if (Buf.st_dev == Buf2.st_dev) |
| 59 | return false; |
| 60 | return true; |
| 61 | } |
| 62 | /*}}}*/ |
| 63 | // UnmountCdrom - Unmount a cdrom /*{{{*/ |
| 64 | // --------------------------------------------------------------------- |
| 65 | /* Forking umount works much better than the umount syscall which can |
| 66 | leave /etc/mtab inconsitant. We drop all messages this produces. */ |
| 67 | bool UnmountCdrom(string Path) |
| 68 | { |
| 69 | if (IsMounted(Path) == false) |
| 70 | return true; |
| 71 | |
| 72 | for (int i=0;i<3;i++) |
| 73 | { |
| 74 | |
| 75 | int Child = ExecFork(); |
| 76 | |
| 77 | // The child |
| 78 | if (Child == 0) |
| 79 | { |
| 80 | // Make all the fds /dev/null |
| 81 | for (int I = 0; I != 3; I++) |
| 82 | dup2(open("/dev/null",O_RDWR),I); |
| 83 | |
| 84 | if (_config->Exists("Acquire::cdrom::"+Path+"::UMount") == true) |
| 85 | { |
| 86 | if (system(_config->Find("Acquire::cdrom::"+Path+"::UMount").c_str()) != 0) |
| 87 | _exit(100); |
| 88 | _exit(0); |
| 89 | } |
| 90 | else |
| 91 | { |
| 92 | const char *Args[10]; |
| 93 | Args[0] = "umount"; |
| 94 | Args[1] = Path.c_str(); |
| 95 | Args[2] = 0; |
| 96 | execvp(Args[0],(char **)Args); |
| 97 | _exit(100); |
| 98 | } |
| 99 | } |
| 100 | |
| 101 | // if it can not be umounted, give it a bit more time |
| 102 | // this can happen when auto-mount magic or fs/cdrom prober attack |
| 103 | if (ExecWait(Child,"umount",true) == true) |
| 104 | return true; |
| 105 | sleep(1); |
| 106 | } |
| 107 | |
| 108 | return false; |
| 109 | } |
| 110 | /*}}}*/ |
| 111 | // MountCdrom - Mount a cdrom /*{{{*/ |
| 112 | // --------------------------------------------------------------------- |
| 113 | /* We fork mount and drop all messages */ |
| 114 | bool MountCdrom(string Path, string DeviceName) |
| 115 | { |
| 116 | if (IsMounted(Path) == true) |
| 117 | return true; |
| 118 | |
| 119 | int Child = ExecFork(); |
| 120 | |
| 121 | // The child |
| 122 | if (Child == 0) |
| 123 | { |
| 124 | // Make all the fds /dev/null |
| 125 | int null_fd = open("/dev/null",O_RDWR); |
| 126 | for (int I = 0; I != 3; I++) |
| 127 | dup2(null_fd, I); |
| 128 | |
| 129 | if (_config->Exists("Acquire::cdrom::"+Path+"::Mount") == true) |
| 130 | { |
| 131 | if (system(_config->Find("Acquire::cdrom::"+Path+"::Mount").c_str()) != 0) |
| 132 | _exit(100); |
| 133 | _exit(0); |
| 134 | } |
| 135 | else |
| 136 | { |
| 137 | const char *Args[10]; |
| 138 | Args[0] = "mount"; |
| 139 | if (DeviceName == "") |
| 140 | { |
| 141 | Args[1] = Path.c_str(); |
| 142 | Args[2] = 0; |
| 143 | } else { |
| 144 | Args[1] = DeviceName.c_str(); |
| 145 | Args[2] = Path.c_str(); |
| 146 | Args[3] = 0; |
| 147 | } |
| 148 | execvp(Args[0],(char **)Args); |
| 149 | _exit(100); |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | // Wait for mount |
| 154 | return ExecWait(Child,"mount",true); |
| 155 | } |
| 156 | /*}}}*/ |
| 157 | // IdentCdrom - Generate a unique string for this CD /*{{{*/ |
| 158 | // --------------------------------------------------------------------- |
| 159 | /* We convert everything we hash into a string, this prevents byte size/order |
| 160 | from effecting the outcome. */ |
| 161 | bool IdentCdrom(string CD,string &Res,unsigned int Version) |
| 162 | { |
| 163 | MD5Summation Hash; |
| 164 | bool writable_media = false; |
| 165 | |
| 166 | // if we are on a writable medium (like a usb-stick) that is just |
| 167 | // used like a cdrom don't use "." as it will constantly change, |
| 168 | // use .disk instead |
| 169 | if (access(CD.c_str(), W_OK) == 0 && DirectoryExists(CD+string("/.disk"))) |
| 170 | { |
| 171 | writable_media = true; |
| 172 | CD = CD.append("/.disk"); |
| 173 | if (_config->FindB("Debug::aptcdrom",false) == true) |
| 174 | std::clog << "Found writable cdrom, using alternative path: " << CD |
| 175 | << std::endl; |
| 176 | } |
| 177 | |
| 178 | string StartDir = SafeGetCWD(); |
| 179 | if (chdir(CD.c_str()) != 0) |
| 180 | return _error->Errno("chdir",_("Unable to change to %s"),CD.c_str()); |
| 181 | |
| 182 | DIR *D = opendir("."); |
| 183 | if (D == 0) |
| 184 | return _error->Errno("opendir",_("Unable to read %s"),CD.c_str()); |
| 185 | |
| 186 | /* Run over the directory, we assume that the reader order will never |
| 187 | change as the media is read-only. In theory if the kernel did |
| 188 | some sort of wacked caching this might not be true.. */ |
| 189 | char S[300]; |
| 190 | for (struct dirent *Dir = readdir(D); Dir != 0; Dir = readdir(D)) |
| 191 | { |
| 192 | // Skip some files.. |
| 193 | if (strcmp(Dir->d_name,".") == 0 || |
| 194 | strcmp(Dir->d_name,"..") == 0) |
| 195 | continue; |
| 196 | |
| 197 | if (Version <= 1) |
| 198 | { |
| 199 | sprintf(S,"%lu",(unsigned long)Dir->d_ino); |
| 200 | } |
| 201 | else |
| 202 | { |
| 203 | struct stat Buf; |
| 204 | if (stat(Dir->d_name,&Buf) != 0) |
| 205 | continue; |
| 206 | sprintf(S,"%lu",(unsigned long)Buf.st_mtime); |
| 207 | } |
| 208 | |
| 209 | Hash.Add(S); |
| 210 | Hash.Add(Dir->d_name); |
| 211 | }; |
| 212 | |
| 213 | if (chdir(StartDir.c_str()) != 0) { |
| 214 | _error->Errno("chdir",_("Unable to change to %s"),StartDir.c_str()); |
| 215 | closedir(D); |
| 216 | return false; |
| 217 | } |
| 218 | closedir(D); |
| 219 | |
| 220 | // Some stats from the fsys |
| 221 | if (_config->FindB("Debug::identcdrom",false) == false) |
| 222 | { |
| 223 | struct statvfs Buf; |
| 224 | if (statvfs(CD.c_str(),&Buf) != 0) |
| 225 | return _error->Errno("statfs",_("Failed to stat the cdrom")); |
| 226 | |
| 227 | // We use a kilobyte block size to advoid overflow |
| 228 | if (writable_media) |
| 229 | { |
| 230 | sprintf(S,"%lu",(long)(Buf.f_blocks*(Buf.f_bsize/1024))); |
| 231 | } else { |
| 232 | sprintf(S,"%lu %lu",(long)(Buf.f_blocks*(Buf.f_bsize/1024)), |
| 233 | (long)(Buf.f_bfree*(Buf.f_bsize/1024))); |
| 234 | } |
| 235 | Hash.Add(S); |
| 236 | sprintf(S,"-%u",Version); |
| 237 | } |
| 238 | else |
| 239 | sprintf(S,"-%u.debug",Version); |
| 240 | |
| 241 | Res = Hash.Result().Value() + S; |
| 242 | return true; |
| 243 | } |
| 244 | /*}}}*/ |
| 245 | |
| 246 | // FindMountPointForDevice - Find mountpoint for the given device /*{{{*/ |
| 247 | string FindMountPointForDevice(const char *devnode) |
| 248 | { |
| 249 | char buf[255]; |
| 250 | char *out[10]; |
| 251 | int i=0; |
| 252 | |
| 253 | // this is the order that mount uses as well |
| 254 | const char *mount[] = { "/etc/mtab", |
| 255 | "/proc/mount", |
| 256 | NULL }; |
| 257 | |
| 258 | for (i=0; mount[i] != NULL; i++) { |
| 259 | if (FileExists(mount[i])) { |
| 260 | FILE *f=fopen(mount[i], "r"); |
| 261 | while ( fgets(buf, sizeof(buf), f) != NULL) { |
| 262 | if (strncmp(buf, devnode, strlen(devnode)) == 0) { |
| 263 | if(TokSplitString(' ', buf, out, 10)) |
| 264 | { |
| 265 | fclose(f); |
| 266 | // unescape the \0XXX chars in the path |
| 267 | string mount_point = out[1]; |
| 268 | return DeEscapeString(mount_point); |
| 269 | } |
| 270 | } |
| 271 | } |
| 272 | fclose(f); |
| 273 | } |
| 274 | } |
| 275 | |
| 276 | return string(); |
| 277 | } |
| 278 | /*}}}*/ |